There’s an historical plaque commemorating the founding of Mother’s Day in Center City, Philadelphia right at City Hall, near the old Wanamaker’s building. It credits Anna Jarvis for the founding of the day, and Anna Orso writes on the fascinating history of both Anna Jarvis and the generations-long effort by different women to create a “Mother’s Day” on the national calendar. Julia Ward Howe’s earlier efforts are fascinating:

While Jarvis is seen as the founder (more on that later…), the Philadelphia Encyclopedia notes Jarvis wasn’t the first person to propose a day honoring moms, and wasn’t even the first person in Philadelphia to do so.
In 1870, Julia Ward Howe — the composer of the Battle Hymn of the Republic — put a “Mother’s Day Proclamation”in Women’s Journal, a weekly publication in Boston. It was titled “Appeal to Womanhood Throughout the World,” and it called on women to use a day denoted “Mother’s Day” to promote peace following the Civil War.
Howe wanted Mother’s Day to be celebrated on June 2. Per the Encyclopedia, several cities did hold special services on that day between 1873 and 1913, but the holiday didn’t reach widespread audiences and was considered “too radical” by some. Still, “in Philadelphia, the Universal Peace Union (UPU), a group dedicated to ending war and eradicating the American military, faithfully celebrated Howe’s holiday for four decades.”
It makes sense that Mother’s Day would be a response to war. Incredible that there is no Universal Peace Union today, given that our military presence and active war involvement is in many ways higher than ever in our history. We have Mother’s Day, but we still need peace.